Muon and Tau as Resonant Extensions of the Electron

In the Standard Model, the masses and lifetimes of charged leptons are empirical inputs. We explore whether these quantities can instead follow from a minimal discrete-structure hypothesis in which the electron is treated as the smallest stable configuration of identical constituents, and heavier charged leptons correspond to symmetry-preserving extensions constrained by coherence and resonance conditions. Within this framework, the muon and tau arise as the first two admissible resonant extensions of the electron reference structure. Their masses follow from constituent counting combined with discrete resonance scaling, matching the experimental values within ≲0.6% without introducing additional particle species, interaction parameters, or fitted thresholds. The same resonance picture implies that these extensions are metastable: once coherent internal modes exist, finite leakage/dephasing provides a natural link between increasing mass scale and decreasing lifetime. We emphasize that this work does not model detailed decay dynamics; it provides a structural consistency argument connecting charged-lepton generations, mass gaps, and lifetime hierarchy under the stated discrete assumptions.